Method for the removal of tetraethyl lead from hydrocarbons



Jan. 15, 1946. I

M. FRIEDMAN 2,392,846 METHOD FOR THE REMOVAL OF TETRAETHYL LEAD FROM HYDROCARBONS I 3 Sheets-Sheet 1 Filed Aug. 17, 1944 INVENTOR. MAURICE FRIEDMAN Wad/m 9.

ATTORNEY Jan. 15, 1946. M, FRIEDMAN 2,392,846

METHOD FOR THE REMOVAL OF TETRAETHY-L LEAD FROM HYDROCARBONS' Filed Aug. 17, 1944 1 :s Sheets-Sheet 2 FIG.3.

INVENTOR.

MAURICE FRIEDMAN BY f ATTORNEY Jam 15, 1946. FR|EDMAN 7 2,392,846

METHOD FOR THE REMOVAL OF TETRAETHYL LEAD FROM HYDROCARBONS Filed Aug. 17, 1944 3 Sheets-Sheet 3 INVENTOR. MAURICE FRIEDMAN ATTORNEY Patented Jan. 15, 1946 ETHYL LEAD EROMHYDRQCARBQNs;

Maurice Friedman, Asbur the United Statesof Am thev Secretary of..War

y Farm-N21, assignorio erica asarepresentedby,

Application August 17, 1944..Se ,ia1 No. 549.952

(01. Hid-449 (Granted under theiact of1'March.3,, 18.83,,as;

amended April 30, 1928; 3'10 .0., G 757 4 7 Claims.

Theinvention described herein may be manufactured and used'by or for the Government forgovernmental purposes, without the payment to me of .anyroyalty thereon.

My invention relates to a method forthe removal of tetraethyllead from gasoline bymeans of chemical agents; No special'equipment is required' except. for the necessary chemicals, anhydrousgstannic" chloride, and activated carbon, and a simple decanting tube. Although the method developed has beendesigned for use with a' -gallon container, it can easily beadapted for larger quantities-- of gasoline. equally efiective in removing tetraethyl lead from both 80'-octan'e gasoline, commonly known as all purpose motor fuel, and IOU-octane gasoline, o mon y no n av t 0 e In order. to obtain maximum efiiciency from method is hydrocarbons whichare -obtaine d in the so-called fcra'cking processes now common-ly used to increase the-yeld of gasoline iromcrudepetroleum.

These olefine-and-diolefine-molecules are-unsat= modern high compression... internal. combustion engines, it: necessary to use -fuels having-high:

octane value uch fuels a produ ed. b ncor-l porating; into the basestock volatile metakcom- Pounds, such as tetraethyl lead, along with these... calledleadscavengers .such. as ethylene dibromide and ethylene dichloride. While such fufils are very efiective for, the, operationof high compression internal combustion engines, they are said to be unsatisfactory for the operation of engines of thelow compression type, such as are utilized in motor-generators, or. for. the. operation. ofother. devices, such as fieldstovestorches and lanterns, designed for use witnfuelfreeofvolatile -metal compounds.

Since leaded asoline-ls the.

of {lead in various partsof these devices.. To sup-r ply lead-free gasoline in the field is difiicult, since.. the requirements for this-type of fuel are com parativelylimited and the problem of supply wouldgbecomercomplicatedif such fuel were .tc be suppliedmegularly; in, the; field; Because Ofl this, it ,has become, necessary; to devisea simple method for: deleading; gasoline inf-the;- field with arminir or-extraneousequipment;,

Gasoline. is an extremely; complex: mixtur -oi.

within range of 80? F. to

agiven-gasoline, it is generally agreed .that due -to the. vastv number:- of isomer and stereoiscnriers,-

Whichiaretpossible, theitotal number ofpossibili=- ties;is;pr0bab1y:4000.- This c mn es vsisffu ther.

auementedby theinr seuce4oftolefineandldie fins only typeofifuel; supplied; in the field, much difiiculty hasbeen en; I countered in the operation of power.&1.1 nits;v field: stoves, torches and lanterns, due to the deposition.

urated with respect to hydrogen; and therefore contain extremely reactive double -lbonds that have a; tendencyto -form-- addition compounds polymerizing to high carbonchain molecules; which often lead to the deposition-of gum in-the intake system and combustion chamber of an engine, field stove, torchand lantern. Such gum formation'is greatlyenhanced-and accelerated by the presence of catalyticchemical agents'of the type-that have possibilities fonuse as rdeleading materials-.-

Tetraethyl lead is a heavy, colorless liquid, soluble in gasoline and inert" under ordinary-exposure to air, light, heat and water, and unreactive.

to all but the mostactiveofi chemical; reagents. Its extreme stability, therefore, makes its-removal;

' dependent upon its conversion to some other-form:

oflead compound insoluble in gasoline.. Sincethe tetraethyl lead molecule is very similar structun ally. and chemically to.,the-.hydrocarbonstin-gasoline, this conversionmust'necessarily besuchihat:

the =characteristlcs iOf :thegasoline are not; materially changed, andyth'e; formation, of.v harmful;

reaction;completelnavoidednor atlea-st keptt a safe minimum.

In zvievt oL-thescomplexity, of; gasoline v:comppsitiorn. and of. the..-extreme. stabi itx of; e aet y lead and its similarity to mosthydrocarbon mole;-

cule it isfimmed at lr nna e t-tha great imsul-ty would; be attached to; finding a; chemical agent which would selectively react withttetra.

ethyl lead Withoutmateriallyafiecting thehydrocarbonmoleculespresent in thegasoline. By my invention I;v have, devised-v a' method. and means. Whichefiectively removes. tetraethyl lead from gasoline without-essentially changing the chemical. andphysical properties. of, theoriginal. fuel.

Th -method deyelopedinmy invention makes,

useof .C. P. or commercial anhydrous stannic chloride, also known. astin tetrachloride, as a means of precipitating tetraethyl leadfromgasoline, the probable reaction. being:

Lead Stannie; Leaddieth'yl Tindiethyl, tetraethyl chloride dichloride dichloride The'lead dichloride-formed isinsolublein gasoline and: can, therefore, be removed by filtration, aftenagitating with a mixture of activated car-v bon;treated withor without an organic amine for thenurposeof breaking up the colloidal solution which isiormed and. adsorbing or absorbin some of the reaction products and residual stannic chloride.

The mechanical features of my method are extremely simple'and require no extraneous equipment except for the package containing the chemicals, a simple tube for decanting and, of

course, a container to carry out the deleading op-' eration. (The one containing the gasoline to be deleaded is used.) The time required to delead gallons of gasoline is approximately 25 minutes;

' itreated gasoline adjusted by means of the valve I don the decanting tube l5 so that the funnel ll of which only 10 minutes is the actuallyworking time during which the operator is'occupied. It is readily possible for one operator to delead three or four batches (-20 gallons) of gasoline at the same time, thus making it possible to'prepare r approximately gallons of deleaded gasoline'inone hour.

The general object of my invention is to provide a simple method for deleading gasoline'in the field with a minimum of extraneous equipment.

Another object of my invention is toprovide a small compact container which encloses the chemicals to be used in thedeleading process.

Another object oi my invention is to provide a smallcompact container which, upon emptying the, contents thereof, can be used as a filtering funnel in the deleading process.

Another object of my invention is to provide an ampoule which is sealed and contains the anhydrous stannicchlor-ide reagent. 7 1

A further object of my invention is to provide a package containing activated carbon.

Other objects and advantages will appear hereinafter from the following description and drawings. 7

Referring to the drawings, which are for illustrative. purposes only:

. Fig. 1' shows achemical package, a filter-funnel assembly and a method of packing deleading chemicals. a

Fig. 2 is'a decanting tube and a complete chemical package. J I Fig. 3 shows the deleading chemicals, the package ready for use as a filter-funnel, 1 1

Fig. 4 shows ariampoule of stannic chloride being emptied into'a container,

"Fig: 5'shows the container being agitated after addition of the ampouleof stannic chloride Fig.6 shows apacka'ge of activated carbon which willbe'emptied into the container of Fig. 4

after agitation in Fi 5.

jFig. 7 shows the container, the decanting tube, the filtering funneland the receiving'container in operation. l

the method of deleading referring to Fig. 3 the'tip it of the ampoule ll containinglS-H m1.

anhydrous stannic chloride 12 is broken and its contents emptied intothe container l3 in Fig. 4

containing 5 gallons of thegasoline to be deleaded. The gasoline is stirred from 3 to 5 minutes byragitating the container [3 as shown in Fig. 5. The package containing 100- 125 grams of the' activated carbon [4 as shown in Fig, 6, prepared by finely powdered activated carbon in a closed container, is then emptied into the containeri3'in Fig. 4 and the gasoline again agitated as shown in Fig. 5 for a period of from 6 to 10 minutes. Reierringto Fig. '7 the decanting tube I5 is inserted and clamped'i'nto position, the con- I tain er, i3 is placed on its side-as illustrated, and then allowed to'stand for 10 minutes, or until such time asgis necessary to allow the main mass of reaction sludge to settle to the bottom ofthe container (3, as will be indicated by the flow of a clear liquid from the decanting tube 15.

will notv overflow. The decanting operation is continued, with the container l3 in its original horizontal 'p sition,--until the flow of gasoline stops.

No further attempt at recovering they remaining gasolineis advisable, since the tube 15 has been purposely designed so that all but approximately one to two quarts of gasoline is recovered; the wasted portion being chiefly mixed to give it one thorough cleaning with gasoline every fifth or sixth deleading operation. The

use of water as a cleansing agent is not'advi sable unless the container i3 is thoroughly dried prior to its reuse, since the presence of even aslight amount of react with tetraethyl lead.

A typica1 gasoline was dure given above, and the analysesof the original gasoline and of the deleaded gasoline follow; iv

Original Deleaded gasoline gasoline Tetraetl yl lead, ml./U,. S. gallon 2. 63 0. 20 A. S. T. M. dissolved gum, mgsJlOO ml 5. 00 15. 00 A. P.'I.jgravity,' degrees A. P. I I 59.34 59. 32 Reid vapor pressure, lba/sq. in. 7. 50 7. 30 Tin sa r None Corrosion,A. S. T. M. copper strip, None 7 'None Color Red i White Octane number, CFB motor metho 80 Oolorless.

Dzstzllatzim range .Orlginal. Deleaded r gasoline gasoline- Initial boiling point-- F 106 104 10%evaporated 142 1 144 20% evaporated 158 .160 174 175 188" 189 h 203 .204

216 a 219 236 '236 25s 25s 292 1 296 I 367 j v '365 98.7 98.0 1.2 i 1.0 0.1, 1.0

From the above analyses, itis innnediately'apparent thatthe deleading procedure reduced the and of course tetraeth'yllead content of 1 the original gasoline The small difierences shown; for some of the other Dropertiesfare well' within the permissible variation of the analytical test methods themselves, and with the' except the' tetra'ethyl lead content; the other properties of the original gasoline have not been materially changed by the dele'ading operation." T e octane number of :the deleaded' gasoline is -lowered octane rating of the base stock.

'deleaded by the proce- 'itjca'n be definitely stated that. ion of" the" dissolved gum value,

has to the removal ot tetraethyl: 1 lead "which was originally used to 'increa'sethe While the form of embodiment of my invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims.

Having thus described my invention I desire to secure by Letters Patent and claim:

1. The method for treating a mixture of liquid hydrocarbon fuel and organolead compound to remove the latter from said mixture, which comprises adding to a predetermined quantity of said mixture a predetermined quantity of anhydrous stannic chloride, agitating the resultant quantity of mixture and anhydrous stannic chloride for a predetermined time, adding an adsorbent to the agitated mixture and anhydrous stannic chloride, agitating the resultant quantity of mixture, anhydrous stannic chloride and adsorbent for a predetermined time, decanting a resultant portion of clear liquid from the said quantity of material, and finally filtering said resultant portion of said clear liquid.

2. The method for treating a mixture of liquid hydrocarbon fuel and organolead compound to remove the latter from said mixture, which comprises adding to a predetermined quantity of raw mixture a predetermined quantity of anhydrous stannic chloride, agitating the resultant quantity of mixture and anhydrous stannic chloride for a predetermined time, adding activated carbon to the agitated mixture and anhydrous stannic chloride, agitating the resultant quantity of mixture, anhydrous stannic chloride and activated carbon for a predetermined time, decanting a resultant portion of clear liquid from said'quantity of material, and finally filtering said resultant portion of said clear liquid.

3. The method for treating a mixture of liquid hydrocarbon fuel and tetraethyl lead to remove the latter from said mixture, which comprises adding to a predetermined quantity of the raw mixture a predetermined quantity of anhydrous stannic chloride, agitating the resultant quanttiy of mixture and anhydrous stannic chloride for a predetermined time, adding activated carbon to the agitated mixture and anhydrous stannic chloride, agitating the resultant quantity of mixture, anhydrous stannic chloride and activated carbon for a predetermined time, decanting a resultant portion of clear liquid from said quantity of material, and finally filtering said resultant portion of said clear liquid.

4. The method for treating a mixture of gasoline and tetraethyl lead to remove the latter from said mixture, which comprises adding to a predetermined quantity of the gasoline and tetraethyl lead a predetermined quantity of anhydrous stanic chloride, agitating the resultant quantity of mixture and anhydrous stannic chloride for a predetermined time, adding activated carbon to the agitated mixture and anhydrous stannic chloride, agitating the resultant quantity of mixture, anhydrous stannic chloride and activated carbon for a predetermined time, decanting a resultant portion of clear liquid from said quantity of material, and finally filtering said resultant portion of said clear liquid.

MAURICE FRIEDMAN. 

